I was playing as HRE last game and when i aged up to age 3 i pulled out the prelate from Aachen chapel to go for relics when i came back a wolf actually started attacking my prelate i put the relic to the Regnitz Cathedral and moved him back Aachen chapel. The wolf continued to attack the Aachen chapel killing (probably) the prelate while he was inside. After this point the Aachen chapel was Bugged and I couldn’t put any other prelate inside.
(i cannot attach photos or a video because apparently i am a new user)
